U.S. Department of Health and Human Services website aspe.hhs.gov/hsp/ccquality, "13 Indicators of Quality Child Care: Research Update", Richard Fiene, Ph.D., Pennsylvania State University, National Resource Center for Health and Safety in Child Care, University of Colorado, 06/2007.
National Association of Child Care Resource & Referral Agencies, website http://www.naccrra.org/for_parents/, "Child Care Aware", Arlington, VA, 2009